Mass and energetic yields of hydrochar from brewer’s spent grain
Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Technological Equipment of Buildings, Kamýcká 129, CZ 165 21 Prague, Czech Republic
Brewer’s spent grain (BSG) was hydrothermally carbonized at combinations of three temperatures (180 °C, 215 °C, 250 °C) and three reaction times (2 h, 5 h, 12 h). For comparison, the corresponding barley malt was also tested at the same conditions. Elemental composition, volatile matter, ash and heating values were determined for original biomasses as well as resulting hydrochars. The mass yield of dry BSG hydrochar ranged from 45 to 73%. The energetic yield defined as retention of total lower heating value in the hydrochar on dry basis ranged from 66 to 85%. Specific lower heating value of dry material rose from 20.6 MJ kg-1 to 30.3 MJ kg-1 at the most severe conditions. Nitrogen and sulphur content in hydrochar were not strongly dependent on reaction conditions.